CN1105755A - Detecting system for elevator steel rope tension on line - Google Patents

Abstract

An online detection device for steel wire rope tension of a hoist, which can directly measure the tension of the steel wire rope, collect data by a single-chip microcomputer, use the steel wire rope as the transmission medium, and use frequency shift keying (FSK) and phase-locked loop frequency modulation circuit (PLL-FM) to perform two-stage Modulation, directional emission through the emission device that rises and falls along the wellbore. The receiving device at the wellhead adopts automatic gain control, narrow-band filter and FM-FSK two-stage demodulation, processes the received signal with a single-chip microcomputer, and realizes online monitoring of wire rope tension through printing, digital display and alarm, which can improve It provides a reliable guarantee for the safe, reasonable and economical operation of the machine.

Description

The invention relates to the technical field of mining equipment diagnosis, in particular to an online detection device for the tension of a steel wire rope of a hoist.

The hoist is the throat of mine transportation. On-line detection of hoist wire rope tension is a powerful means to ensure safe and economical operation of mine hoisting system. Direct measurement of wire rope tension can not only solve the weighing problem of lifting materials, but also can directly observe the force of the lifting wire rope, so that predictive measures can be taken to prevent the occurrence of vicious accidents such as loose rope and tank falling, so that the entire system runs at its best state.

According to my country's "Coal Mine Safety Regulations", the difference between each tension value of a multi-rope hoist and its average value shall not exceed ±10%. experience to estimate. Fushun Coal Research Institute has developed a device for measuring static tension, which can only be measured by the operator standing on the lifting container when the hoist is static, which is inconvenient to use.

The skip hoist is loaded and weighed, and the pressure-magnetic sensor is usually used for "weighbridge" measurement. Since the coal slime at the bottom of the well is often bonded to the container, it is difficult to measure accurately.

When the hoist transports personnel or materials, it may sometimes get stuck in the tank, causing the wire rope to be loose or too tight; sudden start and stop will produce excessive shock and vibration, which may lead to broken rope, tank drop, bucket fall accidents, resulting in personal casualties , equipment damage, seriously affecting production. For this reason, the United States, Britain, Germany and Sweden have successively researched and developed mechanical protection devices, which have greatly improved safety, but the technology is complex and expensive.

The object of the present invention is to overcome the above-mentioned disadvantages and provide a novel online detection device for hoist wire rope tension of the electric device, which aims to improve the operating performance of the mine hoisting system so that it can reach a safe, reasonable and economical operating state.

The invention provides an on-line detection device for steel wire rope tension of a hoist, which is composed of a force sensor, a transmitting device, a transmitting antenna, a receiving device, and a receiving antenna. The wire rope tension signal data measured by the sensor is two-stage modulated by frequency shift keying (FSK) and phase-locked loop frequency modulation circuit (FM). The wire rope is used as the transmission medium, and the intermediate frequency directional transmission is carried out by the transmitting device rising and falling along the shaft. At this time, the receiving device installed in the hoisting room at the wellhead receives the sent signal. The signal is demodulated by the wide-band automatic gain control circuit and narrow-band filter of the receiving device, and then processed by the single-chip microcomputer. In this way, the digital display, printing, measurement and fault alarm of the tension are realized.

Another feature of the online detection device for steel wire rope tension of a hoist in the present invention is that the load cell can be installed as a "gasket" (hydraulic connector) or "wedge" (wedge connector) between the wire rope and Lift the joints between containers.

The hoist wire rope tension on-line detection device of the present invention has the following advantages:

1. It can detect the tension value of each wire rope and its difference from the average value online;

2. Can accurately measure the load of the hoist;

3. Issue adjustment orders in time according to the total lifting weight, take measures to make the load moderate, and ensure safe, economical and reasonable operation;

4. During operation, once it is found that the tension difference of each rope exceeds the specified value or the tension value is too large or too small, a warning will be issued in time for rope adjustment or shutdown inspection to prevent major accidents.

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the schematic diagram according to the hoist wire rope tension on-line detecting device of the present invention;

Figure 2 is a schematic diagram of the installation of the load cell, where (a) is a schematic diagram of the installation of the hydraulic type, and (b) is a schematic diagram of the installation of the wedge type;

Fig. 3 is the circuit diagram of transmitter;

Fig. 4 is the circuit diagram of receiving device;

Figure 1 is a schematic diagram of the principle of the online detection device for wire rope tension of a hoist according to the present invention. The load cell installed on the top of the lifting container 1 converts the tension of the wire rope 3 into pressure. (Refer to Figure 3) This pressure acts on the strain bridge B to output an electrical signal. Then, after the signal is amplified, filtered and A/D converted, the analog signal is converted into a digital signal and sent to the single-chip microcomputer for data processing. The processed signal The frequency shift keying and phase-locked loop frequency modulation circuit (FSK-FM) two-stage modulation is performed by the transmitting device 4, and the transmitting antenna 6 is inductively coupled with the steel wire rope 3, and the steel wire rope is used as the transmission signal medium for directional wireless transmission and data transmission. The signal is transmitted to the winch house at the wellhead and received by the receiving device 5. Referring to Fig. 1 and Fig. 4, it is demodulated by FSK-FM two lines, and then processed by the single-chip microcomputer, and the tension unevenness detection is realized by displaying, printing and alarming , weighing, overload and loose rope (slip) alarm functions.

As can be seen from Fig. 1, the launching device 4 and its power supply battery such as the accumulator bottle 10 must be installed on the top of the lifting container, and can be lifted up and down along the shaft. Usually the depth of the well can reach hundreds of meters to thousands of meters. Various pipelines, steel wire ropes, high-voltage cables and signal lines are laid along the wellbore, so there are many interference clutters. At the same time, there are coal dust, water droplets, stones, etc. falling, and the environment is humid and harsh. In this case, a solid shell that is moisture-proof, waterproof and anti-interference must be used when installing the transmitter to make it work normally.

The load cell 2 is installed at the connection between the wire rope 3 and the hoisting container 1. Figure 2 is a schematic diagram of the installation of the sensor, Figure 2(a) is a hydraulic connector, and Figure 2(b) is a wedge connector. For example, in a hydraulic connector, the load cell 2 is installed between the rope adjusting nut 11 and the hydraulic cylinder 12, and it acts as a "gasket" between the nut and the cylinder. If the load cell is installed between two wedges 17 in the wedge connector, the load cell is also equivalent to a "wedge" from the perspective of force. This installation method can change the tension measurement into the pressure measurement without affecting the original force of the lifting system components, even if the sensor fails, it will not affect the force distribution of each component. Moreover, it is convenient to install and replace, and does not need to newly design the suspension device 18, which is conducive to the technical update of old equipment.

FIG. 3 is a circuit diagram of the transmitting device 4 . The tension signal measured by the strain bridge B of the load cell 2 is filtered by the amplifier A ₁ and the filter (A ₂ , A ₃ ), and then sent to the single-chip microcomputer for processing. The rope-by-rope marshalling passes through the interface circuit, and the function generator After frequency shift keying (FSK) modulation, it is then modulated by a phase-locked loop frequency modulation circuit (FM) and output from the voltage-controlled oscillator V _CO . The phase-locked loop frequency modulation circuit is composed of a phase-locked loop, a crystal oscillator CR and a frequency division circuit (1/M, 1/N), among which the phase-locked loop includes a phase detector PD, a voltage-controlled oscillator V _CO and a loop filter , and then sent to the adder composed of A ₄ , A ₅ , A ₆ , which improves the stability and reliability of the frequency after FSK-FM two-stage modulation. Before the modulated signal is sent to the power amplifier Ta, Tb, it also passes through the follower _A7 , the frequency selection network _L1 , _C1 and the preamplifier _A8 , and finally, it is transmitted and output by the transformer and the output circuit _L2 , _C2 .

The transmitting frequency of the transmitting device is lower than 500KH ₂ , which has no effect on the radio station; the transmitting power depends on the depth and conditions of the shaft, preferably not less than 0.5 watts; the transmission rate is lower than 1200 baud.

The receiving device 5 is placed in the hoisting machine room, and the receiving antenna 7 is installed near the sky wheel 8, as shown in Figure 1, close to the wire rope to pick up the transmitted signal. Fig. 4 is a circuit diagram of a receiving device. L ₁ and C ₁ are input circuits, and A ₁ , A ₂ , A ₃ , D ₁ and A ₄ form an automatic gain control circuit to weaken the standing wave effect. The local oscillator circuit is also composed of crystal oscillator CR, frequency divider (1/M and 1/N) and phase-locked loop (PD ₁ and V _co1 ). Together with the received signal, it is sent to the mixer _A5 , and after being amplified and filtered by _A6 , it is demodulated by _PD2 and V _co2 ; after being amplified by _A7 , it is demodulated by PLL for the second time, and finally sent to the interface It is processed by the single-chip microcomputer, and sent to the printer, the digital display device and the alarm when it is not in normal operation with the output ports _PA , _PB , and _PC of the 8155.

Although the present invention has been illustrated and described using a specific embodiment, the present invention is not limited thereto, and changes and improvements can still be made to the present invention within the concept and scope of the present invention.

Claims (2)

1. An online detection device for steel wire rope tension of a hoist, which is composed of a force sensor, a transmitting device, a transmitting antenna, a receiving device and a receiving antenna, and is characterized in that: the force sensor directly measures the tension of the steel wire rope, and a single-chip microcomputer is used to collect the force sensor The measured steel wire rope tension signal data is two-stage modulated by frequency shift keying (FSK) and phase-locked loop frequency modulation circuit (FM). The wire rope is used as the transmission medium, and the intermediate frequency directional transmission is carried out by the transmitting device rising and falling along the shaft. At this time, the receiving device installed in the hoisting room at the wellhead receives the transmitted signal, and the receiving device installed in the hoisting room at the wellhead receives the transmitted signal. FM-FSK two-level demodulation, and then data processing by single-chip microcomputer, thus realizing digital display, printing, measurement and fault alarm of tension. 2. The online detection device for steel wire rope tension of hoist according to claim 1, characterized in that the load cell can be installed on the wire rope as a "gasket" (hydraulic connector) or "wedge" (wedge connector) connection to the lifting container.

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